Marking device



H. E. OLES MARKING DEVICE Jan. 11, 1949.

Filed July 12, 1945 INVENTOR. fezerf E (/71 5 HTTORNEY Patented Jan. 11,1949 umren PATEN 0F F E. om, fimuan R. Mallory, $130.,acorporationcflnela This 1 invention: relates: tomarkingdevices andmethod and has particular" reference to electrimily: forming: charactersor "designs on: metal;

An; object" of. this invention is to'r'provide improved meuns andmethcdofforming characters Impresent; there'rarer several methods ofproviding'marking, such astnameplates; identifl oationrserial numbers;etc:, onmeta'llic objects; These include hardened: steel stamps whichimposethe characters in the metal and have'the disadvantage oisuhjectingitheipiece toshockand possible distortion: Anothermethod' lstdwrite on themwith av so-calle'd "electric pe'ncill This has thedisadvantagevtha'ti it: is slow: andfdoes not give uniform! work.Another method is on the market whereby a special stencil is made andthen by means-Ora solution"andelectrolytic action the characters areetched into the surface. This has the disadvantage that the" stencilsare expensive, not readily made, and'asolution must be employed,- whichis inconvenient.

The present invention utilizes a method which has none: of thedisadvantages of the foregoing. The invention. comprises. the.application the output of" a high. frequency electrical impulsegenerator toiagroupofmetal projections;- preferably flnaorsharp. metalpoints and soar-ranging these points that. sparks will jump from; themthrough the characteror desisn openings 'of a stencil to a metal objectto be marked. The burning caused by the sparks produces the desiredmarking. The stencils can be produced out of paper from any stencilingmachine. No solutions are employed and the operation is rapid andsimple, producing a permanent mark.

As in Figure 1, the device comprises mainly a high frequency electricalimpulse generator II); a metal object II to be marked, connected to theimpulse generator by a lead I2; 8. stencil sheet I3, mounted on theobject II; and a marking device ll, connected to the impulse generatorby a lead apolis, 1nd,, yassignor to Inc., Indianapolis, Ind.,

ware Application-Jilly 1-2; 1945,S erial-No. 6043811 3 Claims.- (01.219-45) I5. .In operativezposition, the marking device 14 rests onthestencil sheet I3, and marking impulse gaps I6: are thus providedbetween the marking deviceildandithe. object lLthrough the perforationsof the stencil sheet l3.

The circuitof the impulse generator I0 is shown in Figure 5. Whilerelatively low frequencies may be useduitls preferable to providefrequencies of the order of radio frequencies in the output of theimpulse generator particularly since such high frequencies present nodanger to a-ntoperator-"of the device of this invention. A relativelyhigh voltage is preferable so that the sparkingrate through the markingimpulse gaps i is?-high.n0ugh t0 providea substantial and uniformdensityof. dots or marks on the object l I.

The impulse generator circuit has a D. 0. supply and comprises-twooscillatory circuits A and B, The DC. supply to circuit A builds up acharge in a condenser-I1 which breaks down a spark gap- Ill. Theoscillation of the circuit A, with a 2000 volt:D. C. supply, provides asparking frequency across thegap I8 of the order cuit Bi to oscillate;and at a higher frequency, through thecharging of a condenser I9 and thebreaking downof I I and the markin The-gap I6, that is, the thickness ofthe stencil I3, is taken into consideration with respect to'the voltageand the electrical characteristics of vtheimpulse circuits, the objectII, and the marking device l4, so that the gap I6 is short enough topermit arcing in sufiicient stl'cngth to efil'ciently burn the objectII.

Referring to Figures 1 and 2, the object I I is formed ofmetal, forexample, steel, and is provid'e'd'wl'th a convex upper surface to bemarked, in a curvature to which a rolling cylinder may conform. incontinuous overall contact. It is withinithescope' of this inventionthat the surmay-be flat, or may be of any desired curvature andconfiguration, as long as the markin device is so formed as to be ableto conform to such curvature and configuration.

The stencil I3 may be formed of paper or other suitable non-conductingmaterial, and with perforations defining Whatever character is desiredto be formed on the object II.

The marking device ll, of Figures 1 and 3, comprises a roller unit withmetal spark points 20. The marking is accomplished by running theroller, in this case manually, back and forth over the stencil sheet I3as it lies on the object I l.

2,468,871 g ffaiif i smooth outer contact surface, and the ends of thesleeve are closed by centrally perforated plugs 23 of nonconductingmaterial such as Bakelite. A support arm 24 is provided for the rollersleeve 2|, in the form of a metal rod bent back'on itself at itsmidpoint to form a handle portion with two portions of the rod extendingalong a substantial 1 distance together, then outwardly, then parallel,

and finally inwardly toward each other to terminate inside the sleeve 2|in the perforations of the end plugs 23. Thus, the sleeve 2| may berotated on the ends of the support'arm -24. A handle 25 of Bakelite orother insulation material is mounted on the handle portion of thesupport arm 24. Electrical connection from the impulse generator In tothe spark points 20 is made through the lead l5, and a contact arm 26which is secured to the support arm at 21 and is in contact engagementwith the roller sleeve contact portion 22. i

The alternate structure of Figure 4 is shown in out of operationposition and comprises a substantially flat object 28 to be marked, apaper stencil sheet 29 lying on the body 28, and a marking plate30,'comparable to the roller 2| of Figure 1. The plate 39 issubstantially in the form of a metal disc with its operating faceknurled to provide metal points 3| from which sparks are jumped throughthe perforations 32 of the stencil sheet 29 to mark the body 28. Thedesired length of the marking spark gap is provided by the thickness ofthe stencil sheet 29 so that in its position of operation, the markingplate rests on the stencil sheet 29.

The marking plate 30 is provided with a handle 33 for moving the plateinto and out of operating position. With this structure, the markingplate 30 may be applied to the stencil 29 somewhat in the manner of astamp instead of the rolling application of the structure of Figure 1.Thus, the structure of Figure 4 may be used in arrangements where noroom is available for the lateral rolling action of the roller 2|.

The surface to be marked of the body 28 may be of any desired curvatureor configuration, as long as the marking plate 30 is formed to aconforming curvature and configuration. Leads 34 and 35 are provided forconnection with the impulse generator IB and correspond respectively tothe leads I2 and I5 of Figure 1.

Many variations of material, form, and dimension come within the scopeof this invention as disclosed in this specification and the followingclaims, taken in conjunction with the accompanying drawings, since theparticular details provided are simply for illustration.

Having described my invention, I claim:

1. In an electric marking device, a metal object, a stencil mounted upona surface of said object having openings therein defining a pattern tobe marked onsaid surface,;'a metal marking member having projectionsextending therefrom constituting a continuous regular array of sparkelectrodes, and an impulse generator connected .to-said member and saidobject whereby, when the member is moved into contact with the sten cil,sparks pass between said object and said electrodes through the openingsin said stencil therebymarking a'pattern on portions of said surface,the; body ,of the stencil preventing the passage of sparks between thesaid electrodes and the other portions of said surface.

2. In an electric marking device, an object to be marked which is formedof conductive-material, a stencil mounted upon a-surface of said objecthaving openings therein defining a pattern to be marked on said surface,a"roller having'p'rojections extending therefrom constituting a con.-tinuous, regular array of spark electrodes, and an impulse generator-'connected to said, roller and said object whereby, when-the roller ispassed over the stencil, sparks pass between said object and saidelectrodes through the openings in said stencil thereby marking apattern on portions of said surface and the body of the stencil preventsthe passage of sparks between said electrodes and the other portions ofsaid surface. 1 a

3. In an electric marking device, an object having a metal surface to bemarked, astencil mounted on said object having Openings therein defininga pattern to be marked on said surface, a metal marking member having aknurled face with a continuous series of spark points extendingtherefrom, said member being adapted for. con tact with said stencilwhereby. spark :gaps are formed between said surface and the sparkpoints overlying the openings in the stencil and the bodyof the stencilis interposed between said member and the other portions .of saidsurface, and an impulse generator connected to said metal surface andsaid marking membeng HERBERT E. OLESI.

REFERENCES orrnn The following references areof record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 498,973 Garnett June 6, 18931,068,774 Hutchison July 29, 1913 1,289,000 Robinson Dec. 24., 19181,651,074 Steffens Nov. 29, 1927 -1,'795,564 Korge Mar. 10, 1931

